Pull rod carrier



p *T-UNITED STATE Patented Nov.,28, `1944 i f i from, RonoARRIER @nnenRossmmwilmettelnl. ApplieattnMareh 1o, 194i,` seralNo. 382,474

' A ,15claimsl (ciu- 1522er @This invention relates topull rodcarriers,` ,and t more particularly to carriersof the type shown in mypending `application, Serial No. 272,865.

i In :certain oil well districts horizontally` recipe.` rocating` pullrods are usedfor transmitting power frornaicentral` enginelor power toeach ofa plu;-` rallity` of` pumpsjsomeof whichmay `be thousands `ofyfeet distantffrom `the power. Each .pull .rod

which extends from the` power to a pump.` is supi ported` by `carriersevery. twenty-five or so feet` in order `to prevent excessive sagging ofthe pull rod or to prevent dragging on thejground.

neverwinf tension. The `Wear on the bearings is therefore alwaysin thesame directiof` and can thus be readily taken up after considerable wearhas occurred. Also, even beforeitheiwear is taken up `'there willbe noback lashas thecarrier oscillatesffrom` its'centerpositionztojeithertextreme `position,.`since the direction of thestressin'each link remains the same throughout the cycle1o`f The pullrodcarrier 'of the `type withwhichthe present inventionirelates`compris/esa. linkage pivoted 'about two stationaryi pivots and havingone pointthereof which `moves `in substantially a straight horizontalline;` A-pull .rod support is mounted on the carrier atythegstraightlinemotionI point thereof, `and the `pull rod rests upon that supportjAs thepullrodreciprocates it causes the pullxrodj` carrier to swing `with it,and` guides it in subatjone` end about spaced `parallel axes andinter-1connected,` at` their opposite ,ends bya third link.

,Apoint on the perpendicular bisector of the third` link movesin astraight line. `liaedtosupportthe pull rod. p

This `peint is auf 1 In; my; application i Serial No. 272,865, above3referredutd the arms` are "made `ofi considerable length sothat thestraight line `motion point of the mechanismwill lie above thestationarypivots of the arms. In this type. of Roberts mechanism,`

`when the pull rodireaches one extreme position,l 4

all of` the weightonthecarrier is imposed upon one of thearms1and,z in.addition, `that `one arm exerts ya tension on the otherarm. Each arm is`thus lfunden` compression'` duringthe major por--l -tion of the strokeandunder tension at one end` ofthe stroke. a result the Wear on thebearings fis at the top and at thebottomof` the bearing.` Afterthere hasbeen some wear in the bearings play .:develops' due to back lash as thestress on a link` or armfgoesfrom compression ,to` tension. ItV is oneAof the objects` of the present. invention to overcome this difliculty byusing a Roberts `type lof `mechanism which isso proportioned that theSupporting arms are 1always in` compression and Figure is an end viewthereof;`

movement of the pull rod. i Y i L i Itis a further object `of thepresentinvention toprovide a `pull rod carrier `of `theabove-.menf Htioned character with a simple typeof bearing support which will allow aquick assemblypf ythe carrierin the field. `Itis a still further objectof the present invention to provide `anirnprove`- l` carrier` oftheabove mentioned character wherein the arms are comparatively `short thusreducingthe l amount of material required for the carrier.` andalsofreducing the momentum of the moving parts byreducing their` mass.`z' f 1 x l It is a still further 4object ofthe presentin-Y vention toprovide anwimproved carrier of the above` mentioned characterwhereinfthecarrier supporting base acts `as a stop tolimit the motion of thecarrierin each directionwithoutthe addition ofl material to the `basefor, accomplishing` the stopping' function. f f* The attainment oftheabove and lfurtherfolzv jects lof the present invention Vwill beapparent30 `from `the following specification taken in con-` VjunctionV .withthe i accompanying drawing forming a part thereof.; l `j i t i. v Invthe drawing?` f u Figure 1 isy a plan View of acarrierembodying the`present invention;

.Figure `2 `is a front `view of the `uren? i carrier of" Fig- Figure4is'a fragmentary perspective `the carrier of `Figure 1; and

i Figure 5 is a perspectivedisassembled viewof the pullrod support ofthe carrier of Figure 1.

Reference may now beV had more particularly to the drawing,` whereinlike reference` numerals y `designate like parts throughout. `Afpullrodcar- 3rier which isindicated at lisupportsa pullrod i `2thatreciprocateshorizontally. `The pull rodi 2 is oneof a numberof pullrodseachextending from :a sourceof power `to differentpumps `in an i oil`fieldncSome pumps are `comparatively ,closel Ito :the powerandnothersimay be thousands of feetaway.` :The `pull rod 2 issupportedQat regular,V intervals, `approiimat`e1y\twenty--five feetapart,

`by carriersisuchasthe 'carrier "The carrier is viewof theflower end Aofoneof the supportingarms of" This asthe pipe 6. A short second rod I0 isalso welded to the pipe 6. The U-bolt 8 embraces the post 4 and extendsthrough the holes in the pipe 6,

and is secured in place by nuts II threaded on the U-bolt and bearingagainst the rods 9 and I0. The U-bolt thus rmly secures the support-ying rod 9 to the post 4. The supporting rod .9.

is bent at its opposite ends to form arms. I2-I3 constituting pivot rodsor bearing supports. A pair ofxspaced'washers 'I4-I5 are .spot welded toeach bent portion of lthesupporting rod `9. The space lbetween each setlof washers I 4-I 5 consti# tutes' a-bearing support. i

Arms 1r-nuke n-Ia of a straight une eper- 'ating mechanism are eachsupported by the bent portionsfof .the supporting rod between the wash-.ers .I4-'15. The armsor links I1 and I8 are of identical size andconstruction.` Each armcomprises two wooden boards 2IJ-.2I .securedtogether l in .spaced relationship by rectangularbearing blocks.V "Theupper bearing block, indicated at 22, is .merely an oil soaked hard woodblock having .a longitudinally .extending hole therethrough which formsa'bearing. lThe upper bearing block l is bolted to the" boards -2I bytwo bolts 24 that extend through the boards and through the bear- 'ing'block 22. The lower .bearing block, indicated at 2.6,.c'omprises an oilsoaked hard wood block having `a longitudinal slot 21 therein, the topof which slot. terminates in asmooth circular curve 28. vThe lowervbearing block in4 secured between the arms 20-2Iby .two bolts 30 thatpass through the boards 2U-2li and through the arms 3I-3I -of thebearing block 26. l

Ail-shaped link pivotally connects the arms I1-I8. This link comprises asteel rod bent to Z-shape so that ithas parallel arms .S6-31 joined bythe diagonal' portion 38 of the Z. Washers 4II4I are spot welded to Athearms 3.6-3.1 respectively. The Z-shaped link includes' 1a depending rod42 welded to the portion 38 .at the center thereof. The rod 42 is at aslight inclination to a vertical plane determined by the llongitudinalaxis of the pull rod 2,v as may be seen from Figure 3.. At its lower endthe rod42 has a .short steel rod or` stem 43 welded thereto andextending horizontally therefrom. The stem 43 has a. pair of .spacedwashers 44-45 mounted thereon and spot welded thereto. wood block 46 isslipped over the stem 43 between the washers `44-45'.and is secured inplace by a bolt 41. lThe slot in the block 46 terminates at its :top ina smooth circular curve 48which rests on the stem 43. .and turnsthereon. A metal ,strap 4-9 Adepends from the bolt 41 of the block 46.The

pull lrod 2 rests upon that. strap and .may be readily .removedtherefrom merely by lifting the pull rod :2 upwardly.

To assemble the `pull rod carrier the link I1 is 4 A slotted oilsoakedhard corresponding hole in the corresponding block 22 of the link I8until that link abuts against the washer 4I. The lower ends of thelinks'l1 and I8 are then slipped down upon the arms I2 and I3,respectively, between the washers I4 and I5 so that the slots 21 of theblocks 26 embrace the arms I2 and I3 and with the curved surfaces 28 ofthe two blocks resting on the arms I2 and I3. The blocks 26 are thensecured against upward removal by the bolts 30. The Z-shapel link 35 isvnow held against movement in one direction by the washer 46 whichengages one side of the ,link I1 and by the corresponding washer 4Iwhich engages the opposite side of the link I8. The

`strap 49 may Vthen be positioned-on the bolt 41. Thereafter the pullrod may be positioned upon that the link lengths be .of certainproportions with respect to onev another. In vdealing with theseproportions the lengths or distances considered are the center to centerdistances between the respective pivots.

The proportion vof the linkage is such that the path of movement of thecenter 50 ofthe stem 43 is substantially a straight line Within-theiii-nits i of motion ofthe pull rod 2. A suitable linkage for obtainingthis result with a pull rod having astroke of 42 `inchesis of thefollowing proportions:` `distance between the centers of the armsI2-I3,'34 inches; lengths of links I1-I8 from center to center of thearms I2-36 and I3-31, 13 inches; center to center distance `of the arms36-31, 22 inches; center to center distance be tween the stem 43 and thecenter of the Z-.shaped link 35, 30 inches.

Itis to be noted that the axis of the pull rod 2, as seen in Figure 3,is vertically centeredwith respect to the links I1-I8 and the Z-shapedlink 35. This 4eliminates uneven [stresses on 'the bearings tending totwist the links.

As the pull rod moves to the right ofthe posi tion illustrated in Figure2 i't draws the pull rod carrier with it from the full line position toan extreme position illustrated by the dash lines of Figure 2.V At thatextreme position the arm 36 abuts against the supporting rodv 9 andlimits the l extent of motion yof the carrier. Any additional movementof the pull rod 2 to the rightfafter the carrier reaches its limitingposition, results merely in slipping or sliding of the pull rod on thelsupport 49. When the pull rod commences yto move in the koppositedirection it draws the carrier with it from the `das'hpositionillustrated,

.to its center full line position and onward to a position approximatelycorresponding to the `dash position illustrated but on the opposite sideof the center. The-*carrier is proportioned so that the length of thestroke `of the center point 'm .opposite directions, as limited byabutment -of the arm .36` or the arm' 31 against the rod '3,

is slightly inexcess of the maximum stroke of the.. .pull rod 2.Therefore, if the pull rod is re.- moved from the carrier while thecarrieris in anyv position, and replaced onthe. carrier after thekcarrier has moved to another position, then rageesgssz during the firststroke of" the pull rod it willdraw the carrier to one extreme positionor thelother` thereof andthen `slidelonthe carrier` until the pull rodis againtcenteredonthe carrier. `'I'hereafter, during operation ofwthepull rod there will be nofurther `slidingof the pull rodin the strap 49.l l y is anlequal distance from the pivots andis adapted l toreciprocate in a substantially straight line mof tWhen the carrier isinfits mid position the entire weight of the "pull, rod is carried `bythe links` ,l 4I 1`I 8 both of which are in compression.- This continues4even until the carrier reaches its limitl ing position for eveninitsextreme position, i1- ilustrated in dash'lnes of FigureZ, `thelink,I8 is l still on the same side of4 a verti-calplane passingA throughylthe pivot axis J3. The `link i8 `never "passes through a Vertical'position. There-fore, "even: in its extreme position theforce on thelink` `l'l due to the weightofthe pull :rod is still in -beA ,the` caseif the link wereplaced inalternate compression `and tension as `thecarrierjmoves :pull rod carrier moves rfmmloneextreme position "to theother. Fromthe above it is `apparent that the proportioning ofthelinksof the straight line Voperating mechanism is so correlated tothe length of the fstroke ofthe pull rod that the `stopping prisingga`base member; inclined convergingarms l .tion, said' cross memberabutting against thebase `asthe cross memberypivotsga fixed distance inreither direction from fits `mdposition to stop the reciprocating-motionof said. supportat xed `2.1Apparatus ofthe character describedfcom-` l.pivotal'ly supported at one end in spacedrelation ;.said .base member,a member `pivoftally supportedgbetween the opposite endsof the arms, a

support afliXed to said pivotally `supported mem` `ber andlocated `anequal distance from both plvotal `supports i of the pivotally supportedmember `and at a` distance from the said pivots of the last compressionl As aresult `the bearingblocks 22 .and `Ziwearonlyat one surface, whichwould` not :1H

l through `its cycle. This permitsya simple` construction` ofy the`blocks '25,@` Furthermorelnsince the `blocksfare always ingcornpressionany Iwear on the `bearings will not result inback` lash as the actionbfthe carrier is obtained before either arm` Mlil` or I8 passes throughits vertical position. l Wear `on the bearings 22-26merely resultsin aslight `foreshortenine:; of the effective lengths `of the links Il-l8'.This is of such small magnitude as to produce a `negligible effect inthestraight line `travel of the` center 513. Thisis possible `because thelinks IT-I8 are always ,in compression .dur-

`ing the movement of thecarrier fromone eX- treme `position totheyotlfierzA `li the links were in berat'iixed points;

ping the-motion of said member greaterthan` the distance `,between thosepivots, land vadapted to reciprocate `in a substan- ,tially straightline, `arid substantiallybelow the I "basemember, 'the distancesybetweenthe pivots being such that the directionof` swinging movement of eitherarm is reversed as it approaches a vertical position and before itpivots through its vertical: position, andmeans `for positively stopfpivotally supported mem- 3; A pull rod carrier comprising `a base, `across `member pivotally supported at each end by arm u i lmembers ofequal length which are pivotally attached to said base, said crossmember having a part `which is rigidly iixed to the rest ofthe cross`member and depends` to ailevel substantially bey low the base, apullrod support pivoted at a lower `pointofsaid part which point is an equaldistance from `both pivots and isadapted to reciprocate in asubstantially Astraight linemotion, at

\ least @neuf said membersabutting against the tension during pari-cfgthe stroke thenlwear `on theybearings` could not be` tolerated for,under such circumstances 4thecarrier would` knock dur- B y providing a`While I have shown A.the pull rod supported i `from the block V,dliubymeans ofthe strap 49, this 1s i not an indispensablepart of`theqinvention.'` For instance, the pullrod mayrest on` thetop of Vtheblock 46, ii?` desired;` Under such circumstances rthe toplof theblockwould be provided with a yshapedgroove `for receiving the pull rodandhold-` inglitagainst side movement across, the b1ockin the mannerillustrated in my pendingfapplica` Ition, Serial No. 272,8651` i `In`,compliance with the requirements of `thez `patent statutes I havehereshown and described f `apreferred embodiment of myinvention.,It,is,`

however, ,to be understood `that the invention, is l not limited to theprecise constructionhere shown,

the Samebeing merely illustrative of` the prin` i, rciples ofth,einvention` What I consider new and: l fdsire to secure by. LettersPatent is:

, "1. A pull rod carrier comprising a base, a cross` member pivotallysupported at each end by armsI -of equal iengthvwhieh are pivotauyattaclmedto,Y said base, said cross member having a part which isrigidlyxed to the rest of the cross member and depends from a linejoiningthe pivots atthe" port at a xed point.

base to Ystop the reciprocating motion of said supl :41 Apparatus ofthecharacterdescribed com-` i prisinga base member, armspivotallylsupported at one end in spaced Vrelation `by said base mem- 1lber, a, cross member pivotally supported between theopposite ends `of`the arms, a support alxed to said cross member and located an equal disftance from both pivotal supports of the cross member `and at a distancefromthe said pivots `of the last member greater than the distancebetween those pivots, and `adapted* to reciprocate in "a substantiallystraight-line` said `cross. member moving into abutment with" the baseat a point adjacent the pivot between thecross member and at least oneof thearms for positively stopping themotion of said support at xedpoints. 5;,Apparatus of the character vdescribed comprising a basemember, upstanding armspivotally supportedin spaced relation bysaid basemember, a depending member\;pivotal1y supported intermediate the upperendsof said `arms and depending below thebasemember, a support affixedto said depending member below the base member adapted toreciprocate-in. a substantially straight line, a `portionof thedepending member that is adjacent the pivot between it `and each armabut- ,-tinggthe base memberas the arms pivot, for posi` xed points.

tively stopping-,themotion ofsaid support at 6s In combination with ahorizontal `longitudilnally reciprocating pull rod, vapull` rod carriersupporting the rod and comprising a straight line l `operatingmechanismpivoted about two spaced `parallel horizontal axes abovethepull rod and at right ang-les theretoiand adistance apartless than l i'3 ends of the` cross member, a pullrod support piv"` noted at a lowerpointof said depending part which the stroke of the ro'd, and a pull rodsupport pivoted .on the carrierat a straight line vmotion point thereofbelow said parallel axes, said pull rod resting :on said-support, f

7'. Aistraight VVline operating mechanism comprising a support, a pairyof equal arms pivoted on the support and extending upwardly therefrom, alink pivotally'connecting the upper ends of the arms and having adepending portion extending below the support and having a lpointthereofv below the support movable in a straight line, said linkv beingmovable into a position in abutment with the support as Vthe straightline mechanism operates, thereby limiting the stroke of the mechanism.

l 8.-'A straight line operating mechanism lcomprising a support, la pairof equal length upstanding arms pivoted on said suppo-rt, and aZ-'shaped cross member pivotally connecting and supported by 'the arms,said'cross member overlying the support and being moved into abutmentwith the support as the arms pivot in either direction from va, midposition, to limit the movement of "thee mechanism in each directionfrom the lmid position.

l 9.v A straight line operating mechanism Icomprising a' support havingspaced parallel horizontal stationary pivot rods, a pair of arms ofequallengths each of which has a bearing block at its 'lower end, thebearing blocks being slottedv with the'slotted portion of each blockembracing a rod and resting thereon whereby the arms are pivoted on therods, a cross member pivotally con- 4nect'ing the upper ends of the armsand having a vvdepending portion a point of `which is located an equaldistance from the lpivotal connections bejtween the arms and the crossmember.v

`ing the extent of insertion ofthe arms into the bearing blocks, meanspivotally supporting the opposite yends of the links, and means at saidopposite ends for restraining the links from movement in a directionlongitudinally of said arms. ll. A linkage comprising a Z-shaped crossmember having parallel arms joined by a diagonal member, a pair ofequallinks having Ybearing blocks at one end, the arms of the crossmember extending each through one of the bearing blocks, stop means onleach ofthe arms between the di1 ll-11n combination with ahorizonta-llongitudinally :reciprocating pull rod, a pull rod'carrier.supporting the rod vand comprising a straight line operating mechanismhavinga pair of equal arms `pivoted about spaced stationary axes, :a`cross vmember pivotally joining the arms 'to swing `about two movableaxes, a pull rod support carried rby the cross member at a point whichis an equal distance from the two movable axes, the length of an armplus the distance between the movable axes being less than; thehypotenuse of a lright triangle of which one arm and the distancebetween the stationary axes constitute the othertwo sides, whereby thedirection of swingofeither arm is reversed as the arm approaches avertical position and before it pivots through avertical position, thedistance between the fixed axes being" less than the stroke of the rod.

13. A straight line mechanism comprising a four 'link chain pivotedtogether to constitute a quadrilateral, said chain including twoopposite links of equal effective lengths and two ofv un'- equallengths, the smaller of the two unequallin'ks overlying the'other of thetwo lunequallinks and being moved into 'abutment therewith asl` theequal links pivot in either direction from a mid position, to limit theactuation of the mechanism in each direction from the mid position. y14. A' carrier comprising a four link chain pivoted together toconstitute a quadrilateral', two of the links being of equal effectivelengths and the other ltwo of `unequal lengths, supporting meanscomprising a pivot and means maintaining said pivot spaced a fixeddistance from one of said unequal links and spaced substantiallyequidistant from the two pivots of said one of the junequal links, thelonger of said two Vlast mentioned links also constituting a supportingmeans; a support for the carrier at one of said supporting means, the,other supporting means including means for supporting a horizontallyreciprocating rod, the reciprocation lof the rod actuating the agonalmember and the bearing block for limiting the extent of insertion of thearms into the bearing blocks, the `bearing blocks being slidable alongthe arms in a direction away from the diagonal -mem`ber and the stopmeans, means pivotally shanks embraced by the slotted portionof` saidslotted blocksand supporting said blocks.

linkage in a to and fro motion, a part of one of the links of the chainbeing moved into abutment with a part of another link of the chain atpoints slightly beyond the limitsof the stroke of the rod to limit theactuation of the carrier.

15. A pull rod carrier for a reciprocating subf stantially horizontalpull rod of such length vas-to a pair of equal links, means holding theends of the links a xed distance apart and providing parallel pivot axesa xed distance apart, a cross f member pivotally joining the links,another pivot axis, means/including the cross member for maintaining thepivots between the cross member and the links at xed equal distancesfrom said other pivot axis, said other pivot axis and the i-lrstmentioned pivot axes being relatively movable with respect to oneyanother in a straight line under the guidance ofthe cross member andthe said links, said cross member overlying and being moved intoabutment with a part of the carrier as the links pivot in eitherdirection from a mid position, to limit the actuation of the carrier ineach direction from the mid position. Y,

ALLEN M. ROSSMAN; f

